JPS6363879B2 - - Google Patents
Info
- Publication number
- JPS6363879B2 JPS6363879B2 JP55177387A JP17738780A JPS6363879B2 JP S6363879 B2 JPS6363879 B2 JP S6363879B2 JP 55177387 A JP55177387 A JP 55177387A JP 17738780 A JP17738780 A JP 17738780A JP S6363879 B2 JPS6363879 B2 JP S6363879B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- nuclear fuel
- gas
- container
- fuel assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 48
- 239000003758 nuclear fuel Substances 0.000 claims description 36
- 239000007789 gas Substances 0.000 claims description 31
- 239000000112 cooling gas Substances 0.000 claims description 7
- 238000013021 overheating Methods 0.000 claims description 5
- 239000000498 cooling water Substances 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- 238000007789 sealing Methods 0.000 claims description 2
- 238000005259 measurement Methods 0.000 claims 1
- 238000000034 method Methods 0.000 description 17
- 230000000712 assembly Effects 0.000 description 7
- 238000000429 assembly Methods 0.000 description 7
- 238000001035 drying Methods 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 239000000446 fuel Substances 0.000 description 4
- 230000035939 shock Effects 0.000 description 4
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000011038 discontinuous diafiltration by volume reduction Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 150000004677 hydrates Chemical class 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
Landscapes
- Cleaning By Liquid Or Steam (AREA)
Description
【発明の詳細な説明】
本発明は、核燃料集合体、特に軽水冷却型原子
炉に挿入される核燃料集合体に付着した水垢を除
去する方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing limescale deposited on a nuclear fuel assembly, particularly a nuclear fuel assembly inserted into a light water cooled nuclear reactor.
原子炉に装荷された核燃料集合体は、長期間使
用しているとその表面に冷却水中の水垢が付着す
る。水垢の主成分は主として酸化鉄（Fe2O3）よ
りなる各種金属酸化物の水和物である。水垢が核
燃料集合体に付着すると、燃料棒からの熱除去が
阻害され、熱効率が低減するのみならず、燃料被
覆管の腐食特性に悪影響を及ぼしたり、燃料棒表
面で放射化された水垢の蓄積により放射線量率の
増加を来たす。 When nuclear fuel assemblies loaded in a nuclear reactor are used for a long period of time, water scales from the cooling water adhere to their surfaces. The main components of limescale are hydrates of various metal oxides, mainly consisting of iron oxide (Fe 2 O 3 ). When limescale adheres to nuclear fuel assemblies, it not only impedes heat removal from the fuel rods and reduces thermal efficiency, but also adversely affects the corrosion characteristics of the fuel cladding, and the accumulation of radioactive water scale on the fuel rod surfaces. This causes an increase in the radiation dose rate.
この核燃料集合体に付着した水垢を除去する方
法として、提案された方法に、超音波による方
法、化学薬品による方法がある。しかし、前者の
方法は核燃料集合体の一部表面の水垢のみしか除
去できず、また、後者の方法は化学薬品を使用す
るため、核燃料集合体への影響が懸念されるだけ
でなく、使用した化学薬品の処理が困難である。 Methods that have been proposed for removing limescale adhering to nuclear fuel assemblies include a method using ultrasonic waves and a method using chemicals. However, the former method can only remove limescale from a portion of the surface of the nuclear fuel assembly, and the latter method uses chemicals, which not only raises concerns about the impact it may have on the nuclear fuel assembly. Difficult to process chemicals.
また、最近では水中で高圧水を吹き付ける方法
も考えられているが、この方法は核燃料集合体に
機械的な衝撃が加わるため問題がある。 Recently, a method of spraying high-pressure water underwater has also been considered, but this method has problems because it applies mechanical shock to the nuclear fuel assembly.
本発明は、化学薬品を使用せず、核燃料集合体
に機械的な衝撃を与えず、核燃料集合体に付着し
た水垢を効果的に除去する方法を提供することを
目的とし、水垢の付着した核燃料集合体を水中に
設置された容器内に密閉する工程と、該容器内に
乾燥冷却気体および水を交互に流入させ、前記水
垢を水中に剥離させる工程と、前記乾燥冷却気体
の流量を、前記容器の流入口および流出口付近の
気体温度の測定結果により制御して、前記核燃料
集合体の過熱を防止する工程とを有することを特
徴とするものである。 The present invention aims to provide a method for effectively removing water scale attached to a nuclear fuel assembly without using chemicals or applying mechanical shock to the nuclear fuel assembly. a step of sealing the assembly in a container placed in water; a step of alternately flowing dry cooling gas and water into the container to exfoliate the limescale into the water; and adjusting the flow rate of the dry cooling gas to The method is characterized by comprising a step of controlling the temperature of the gas near the inlet and outlet of the container to prevent overheating of the nuclear fuel assembly.
すなわち、本発明は、水で膨潤状態の水垢と、
乾燥状態の水垢との間に体積差があり、核燃料集
合体に付着した水垢をこれら二つの状態に交互に
さらすと、水垢は核燃料集合体から剥離する点に
着目してなされたものである。 That is, the present invention provides water scale that is swollen with water,
This method was developed based on the fact that there is a difference in volume between water scale in a dry state, and if water scale adhering to a nuclear fuel assembly is exposed to these two conditions alternately, the scale will separate from the nuclear fuel assembly.
以下、実施例について説明する。 Examples will be described below.
第１図は、一実施例を実施するため装置を示す
もので、１は、水中に設置された容器で、この中
に水垢の付着した核燃料集合体２が収納、密閉さ
れる。この容器１には、乾燥気体の給排系３と水
の給排系４が設けられている。 FIG. 1 shows an apparatus for carrying out one embodiment. Reference numeral 1 denotes a container installed in water, in which a nuclear fuel assembly 2 with scales attached is housed and sealed. This container 1 is provided with a dry gas supply/discharge system 3 and a water supply/discharge system 4.
乾燥気体の給排系３は、ガス貯蔵タンク３１
と、ガス貯蔵タンク３１または容器１からのガス
が弁３２を介して導かれ乾燥冷却する乾燥冷却器
３３と、ガス流入用ポンプ３４と、容器１のガス
流入口３５およびガス流出口３６付近に設けられ
ている熱電対３７，３８とを有し、水の給排系４
は、弁４１を介して容器１の給水口４２から水を
供給するポンプ４３と、容器１の排水口４４から
弁４５を介して水を排出する排水ポンプ４６と、
排出された水のろ過器４７と、処理水タンク４８
とを有している。 The dry gas supply and exhaust system 3 includes a gas storage tank 31
, a drying cooler 33 for drying and cooling gas from the gas storage tank 31 or container 1 through a valve 32, a gas inflow pump 34, and a gas inlet 35 and a gas outlet 36 of the container 1. The water supply and drainage system 4 has thermocouples 37 and 38 provided therein.
a pump 43 that supplies water from a water supply port 42 of the container 1 via a valve 41; a drain pump 46 that discharges water from a drain port 44 of the container 1 via a valve 45;
Filter 47 of discharged water and treated water tank 48
It has
次に、この装置を用いて水垢を除去する方法に
ついて説明する。 Next, a method for removing limescale using this device will be explained.
(1) 水垢の付着した燃料集合体２を、水中に設置
した容器１内に収納し、密閉する。(1) The fuel assembly 2 with limescale adhering to it is placed in a container 1 placed in water and sealed.
(2) 次に、弁４５を開いて、容器１内の水を排水
ポンプ４６を用いて排水口４４から排除する。
排除された水はろ過器４７を経て処理水タンク
４８に入る。(2) Next, open the valve 45 and drain the water in the container 1 from the drain port 44 using the drain pump 46.
The rejected water passes through a filter 47 and enters a treated water tank 48.
(3) 水の排除された容器１内に、ガス貯蔵タンク
３１内に貯蔵されている空気、アルゴン、ヘリ
ウム等の圧縮ガスを気体乾燥冷却器３３を通し
て乾燥冷却状態にしたものをガス流入用ポンプ
３４を用いてガス流入口３５より流入させ、容
器１内を乾燥冷却ガスで満たす。容器１内に流
入されるガスは冷却されているので、崩壊熱に
よつて核燃料集合体が過熱するのを防止するこ
とができる。また、この際ガス流入口３５とガ
ス流出口３６の付近に設けられている熱電対３
７，３８によつてガスの温度の測定を行ない、
その結果を用いてガスの流量を制御するように
するので、核燃料集合体２の過熱を効果的に防
止することができる。(3) A gas inflow pump is used to dry and cool compressed gas such as air, argon, helium, etc. stored in the gas storage tank 31 through the gas drying cooler 33 into the container 1 from which water has been removed. 34 to flow in from the gas inlet 35 to fill the inside of the container 1 with dry cooling gas. Since the gas flowing into the container 1 is cooled, it is possible to prevent the nuclear fuel assembly from overheating due to decay heat. Also, at this time, a thermocouple 3 provided near the gas inlet 35 and the gas outlet 36
7, 38 to measure the temperature of the gas,
Since the gas flow rate is controlled using the result, overheating of the nuclear fuel assembly 2 can be effectively prevented.
例えば、容器２として、直径30cm、高さ500
cmの円筒型の容器を用い、乾燥冷却ガスに約10
℃の乾燥冷却空気を用い、約４気圧でガス流入
口３５から流速約0.4m3／secで流入させた場
合、崩壊熱による核燃料体の発熱量は、原子炉
を停止して１週間後で約10kcal／secと推定さ
れるので、核燃料集合体の表面温度を約40〜50
℃に保持することが可能で、核燃料集合体の過
熱を防止することができる。 For example, as container 2, the diameter is 30 cm and the height is 500 cm.
Using a cylindrical container of cm, add approximately 10 cm to the dry cooling gas.
When using dry cooling air at a temperature of approximately 4 atm and flowing at a flow rate of approximately 0.4 m 3 /sec from the gas inlet 35, the amount of heat generated by the nuclear fuel due to decay heat will be approximately 1 week after the reactor is shut down. Since it is estimated to be about 10 kcal/sec, the surface temperature of the nuclear fuel assembly is about 40 to 50 kcal/sec.
℃, which prevents the nuclear fuel assembly from overheating.
(4) 容器１内に流入したガスは、核燃料集合体２
に付着した水垢の水分を吸収し、水垢を構成す
る酸化物粒子の水分が除去され、水垢の体積が
減少する。この体積減少による水垢の収縮は約
40〜70％におよび、水垢と核燃料集合体表面と
の付着状態が悪くなり、水垢が剥離または剥離
し易い状態になる。水垢の水分を吸収したガス
は、容器１のガス流出口３６から弁３２を介し
て気体乾燥冷却器３３に送られ、乾燥冷却ガス
に再生される。(4) The gas that has flowed into the container 1 is transferred to the nuclear fuel assembly 2.
The water in the oxide particles that make up the scale is removed, and the volume of the scale is reduced. The shrinkage of limescale due to this volume reduction is approximately
When it reaches 40 to 70%, the adhesion between water scale and the surface of the nuclear fuel assembly deteriorates, and the water scale becomes easily peeled off or peeled off. The gas that has absorbed water from the limescale is sent from the gas outlet 36 of the container 1 via the valve 32 to the gas drying cooler 33, where it is regenerated into dry cooling gas.
なお、例えば、容器１として直径30cm、高さ
500cmの円筒型の容器を用いた場合、容器１内
の水を排除した直後に、核燃料集合体表面およ
び容器内表面は約３Kgの水で濡れているので、
この水分を完全に除去するには、流入ガスの流
速が約0.4m3／secの場合で約３分必要である。 For example, container 1 has a diameter of 30 cm and a height of
When a 500 cm cylindrical container is used, the surface of the nuclear fuel assembly and the inner surface of the container will be wet with approximately 3 kg of water immediately after the water in container 1 is removed.
To completely remove this moisture, approximately 3 minutes are required when the flow rate of the incoming gas is approximately 0.4 m 3 /sec.
(5) このようにして、核燃料集合体２を十分乾燥
した後、水の給排系４の給水口４２より水を流
入させると、水垢は核燃料集合体の表面から剥
離して水中へと除去される。水中に移行した水
垢は、排水口４４を通り、ろ過器４７に捕集さ
れる。(5) After the nuclear fuel assembly 2 has been sufficiently dried in this manner, when water is introduced from the water supply port 42 of the water supply/drainage system 4, lime scale is peeled off from the surface of the nuclear fuel assembly and removed into the water. be done. The limescale that has migrated into the water passes through the drain port 44 and is collected by the filter 47.
(6) (2)から(5)までの操作を繰り返す。この繰り返
しによつて、核燃料集合体表面に付着した水垢
が効果的に除去される。(6) Repeat steps (2) to (5). By repeating this process, water scale adhering to the surface of the nuclear fuel assembly is effectively removed.
この実施例の水垢の除去方法は、比較的簡単な
装置で核燃料集合体に付着した水垢を効果的に除
去することが可能であり、また、機械的衝撃を与
えず、化学薬品も用いないので、水垢除去後の核
燃料の炉内再使用に関しても全く問題がない。 The water scale removal method of this example can effectively remove water scale attached to nuclear fuel assemblies with a relatively simple device, and also does not apply mechanical shock or use chemicals. There is no problem with reusing the nuclear fuel in the reactor after descaling.
第２図は、他の実施例を実施するための装置の
要部の構成を示すもので、第１図と同一部分には
同一符号が付してあるが、この装置が第１図の装
置と異なるところは、容器１内にガスおよび水の
かくはん用のかくはん装置５が設けられている点
で、この装置を用いる場合には、容器１内のガス
をかくはんすることができるので、核燃料集合体
２の除熱および乾燥効果を増大させることができ
る。 FIG. 2 shows the configuration of the main parts of an apparatus for carrying out another embodiment, and the same parts as in FIG. 1 are given the same reference numerals. The difference is that a stirring device 5 for stirring gas and water is provided in the container 1. When this device is used, the gas in the container 1 can be stirred, so the nuclear fuel assembly The heat removal and drying effects of the body 2 can be increased.
以上の如く、本発明の核燃料集合体に付着した
水垢の除去方法は、化学薬品を使用せず、核燃料
集合体に機械的な衝撃を与えず、核燃料集合体に
付着した水垢を効果的に除去することができ、産
業上の効果の大なるものである。 As described above, the method for removing water scale adhering to nuclear fuel assemblies of the present invention effectively removes water scale adhering to nuclear fuel assemblies without using chemicals or applying mechanical shock to nuclear fuel assemblies. This has great industrial effects.
第１図は、本発明の核燃料集合体に付着した水
垢の除去方法の一実施例を実施する装置の系統
図、第２図は、同じく他の実施例を実施する装置
の要部の構成図である。
１……容器、２……核燃料集合体、３……乾燥
気体の給排系、４……水の給排系、３１……ガス
貯蔵タンク、３３……気体乾燥冷却器、３７，３
８……熱電対。
FIG. 1 is a system diagram of an apparatus for implementing one embodiment of the method for removing water scale attached to a nuclear fuel assembly of the present invention, and FIG. 2 is a configuration diagram of the main parts of an apparatus for implementing another embodiment. It is. 1... Container, 2... Nuclear fuel assembly, 3... Dry gas supply/discharge system, 4... Water supply/discharge system, 31... Gas storage tank, 33... Gas drying cooler, 37,3
8...Thermocouple.
Claims (1)
れた容器内に密閉する工程と、該容器内に乾燥冷
却気体および水を交互に流入させ、前記水垢を水
中に剥離させる工程と、前記乾燥冷却気体の流量
を、前記容器の流入口および流出口付近の気体温
度の測定結果により制御して、前記核燃料集合体
の過熱を防止する工程とを有することを特徴とす
る核燃料集合体に付着した水垢の除去方法。1. A step of sealing a nuclear fuel assembly with water scale in a container placed in water, a step of alternately introducing dry cooling gas and water into the container to peel off the water scale into the water, and a step of the dry cooling. water scale attached to a nuclear fuel assembly, comprising the step of controlling the flow rate of gas based on the measurement results of the gas temperature near the inlet and outlet of the container to prevent overheating of the nuclear fuel assembly. How to remove.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17738780A JPS57100400A (en) | 1980-12-15 | 1980-12-15 | Method of removing fur to adhere to nuclear fuel assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17738780A JPS57100400A (en) | 1980-12-15 | 1980-12-15 | Method of removing fur to adhere to nuclear fuel assembly |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57100400A JPS57100400A (en) | 1982-06-22 |
| JPS6363879B2 true JPS6363879B2 (en) | 1988-12-08 |
Family
ID=16030044
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17738780A Granted JPS57100400A (en) | 1980-12-15 | 1980-12-15 | Method of removing fur to adhere to nuclear fuel assembly |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57100400A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04137081A (en) * | 1990-09-28 | 1992-05-12 | Fuji Photo Film Co Ltd | Ic memory card with eeprom |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58189597A (en) * | 1981-12-28 | 1983-11-05 | 株式会社東芝 | Method and device for removing fur of fuel rod |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5790200A (en) * | 1980-11-26 | 1982-06-04 | Tokyo Shibaura Electric Co | Method and device for removing water scale |
-
1980
- 1980-12-15 JP JP17738780A patent/JPS57100400A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5790200A (en) * | 1980-11-26 | 1982-06-04 | Tokyo Shibaura Electric Co | Method and device for removing water scale |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04137081A (en) * | 1990-09-28 | 1992-05-12 | Fuji Photo Film Co Ltd | Ic memory card with eeprom |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57100400A (en) | 1982-06-22 |
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